JP4728009B2 - Fiber manufacturing method and fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber manufacturing method capable of preventing the generation of the lowering of transmittance of a fiber and the lowering of softness and toughness of a coat-covered fiber while securing properties of a coating material and improving adhesion to a glass fiber outer peripheral surface and to provide the fiber. <P>SOLUTION: The fiber manufacturing method for manufacturing the fiber 12 is provided with a process for forming a fiber preform 12 by drawing the preform 12a in a state wherein the preform 12a is heated and melted in a heating furnace, a process for pre-coat treating the outer peripheral surface of the fiber preform 12, a process for coating a light screening coating material on the outer peripheral surface of the fiber preform 12 and a process for forming a light screening coating material layer 14 by curing the light screening coating material in a curing furnace. The process for pre-coat treating the outer peripheral surface of the fiber preform 12 includes a process for performing a pre-treatment spraying a plasma gas to the fiber preform 12 by an atmospheric pressure plasma device 24. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a fiber manufacturing method and a fiber using the manufacturing method, for example, a fiber manufacturing method and a fiber manufacturing method having a light-shielding coating agent in an image guide of a multicomponent glass material used in the field of endoscope. Fiber.

  Generally, a glass fiber is used as an optical fiber for transmitting light and an image guide for transmitting images. As a base material of glass fiber, synthetic quartz having excellent heat resistance and transparency is generally used. The outer sheath of the fiber is coated with a two-layer coating of a high modulus resin material and a low modulus resin material so that the fiber is protected from external forces and impacts and the fiber can be bent freely. Has been.

  For such a coating agent, a thermosetting resin material often uses a UV curable coating agent that can be quickly cured due to the disadvantage that it takes a long time to cure. For example, in an ultraviolet curable resin-coated optical fiber disclosed in Patent Document 1, an ultraviolet curable resin material typified by a low elastic modulus urethane acrylate is coated on a primary coating of a silica-based optical fiber, and a secondary coating includes It coats an ultraviolet curable resin with a high elastic modulus. In Patent Document 2, the primary coating is coated with a hard silicone material, and the secondary coating is coated with a soft silicone resin material.

Further, in the case of a quartz base material, the heat melting temperature is inevitably high (1000 ° C. or higher), so that a metal coating with a high heat resistance is used, or an optical fiber as disclosed in Patent Document 3 is used. There is provided a coating agent composed of a borosiloxane resin, silicon dioxide, and an inorganic pigment that counteracts the drawbacks of the metal coating agent having a high initial transmission loss.
Japanese Patent No. 2660278 Japanese Utility Model Publication No. 4-40177 Utility Model Registration No. 2601718

  In the case of a multi-component glass material, it can be melted at a heating and melting temperature of less than 1000 ° C. without requiring a high temperature like a quartz glass material. However, since multi-component systems contain various oxide compounds, they are colored when the illuminance of the ultraviolet curing device is high, leading to a decrease in transmittance. In addition, in the two-layer coating, the integrated light amount of ultraviolet rays is doubled, and further, the transmittance decrease due to coloring is accelerated.

  In order to avoid such problems, if the illuminance of ultraviolet rays is set low, for example, the light arrival ratio near the interface between the light-shielding coating agent and the fiber preform decreases, and the coating agent is uncured or the outer periphery of the fiber There is a possibility that the covering power of the resin may be reduced.

  The present invention was made to solve such a problem, and the object of the present invention is to reduce the transmittance of the fiber while ensuring the physical properties of the coating agent and improving the adhesion to the outer peripheral surface of the glass fiber. It is an object of the present invention to provide a fiber manufacturing method and a fiber that can prevent a decrease in flexibility and toughness of a coated fiber.

In order to solve the above-described problems, a fiber according to the present invention is formed by drawing a preform with the preform drawn in a state where the preform is heated and melted in a heating furnace, and coating the outer peripheral surface of the fiber preform before coating. And applying a light-shielding coating agent having at least one of ultraviolet light and visible light to the outer peripheral surface of the fiber preform and infrared curing by infrared rays, and curing the light-shielding coating agent in a curing furnace. A light-shielding coating agent layer is formed, and the light-shielding coating agent is irradiated with the light energy prior to the infrared ray to be temporarily cured, and after the light energy irradiation, the infrared ray is irradiated to be completely cured. It is characterized in that the light-shielding coating agent is more transparent than when the infrared light is irradiated first and the light energy is irradiated later .

For this reason, the adhesive force between the fiber preform and the light-shielding coating agent layer can be improved by thermal curing with infrared rays while achieving rapid curing of the light-shielding coating agent with ultraviolet rays or visible light .

Preferably, the light-shielding coating agent layer has a plastic hardness Shore A75 or more, and an adhesion force of the light-shielding coating agent to the fiber preform after light energy curing and heat curing is 14 MPa or more .

For this reason, it is possible to ensure damage prevention by the force or impact from the outside of the fiber and the flexibility and toughness of the coated fiber .

Further, in order to solve the above-mentioned problems, a fiber according to the present invention is formed by drawing the base material in a state where the base material is heated and melted in a heating furnace, and forming an outer peripheral surface of the fiber base material. Pre-coat treatment, apply a light-shielding coating agent to the outer peripheral surface of the fiber preform, irradiate the light-shielding coating agent with light energy to primarily cure the light-shielding coating agent, and after the primary curing, infrared rays The light-shielding coating agent is irradiated to form a light-shielding coating agent layer by secondarily curing the light-shielding coating agent, and the infrared light is irradiated first and the light energy is irradiated later. The transparency of the light-shielding coating agent is increased .

For this reason, the adhesive force between the fiber preform and the light-shielding coating agent layer can be improved by thermal curing with infrared rays while achieving rapid curing of the light-shielding coating agent with light energy .

Preferably, the light energy is at least one of ultraviolet rays and visible rays .

For this reason, the adhesive force between the fiber preform and the light-shielding coating agent layer can be improved by thermal curing with infrared rays while achieving rapid curing of the light-shielding coating agent with ultraviolet rays or visible light .

In order to solve the above problems, a fiber manufacturing method according to the present invention includes a step of forming a fiber preform by drawing the preform in a state where the preform is heated and melted in a heating furnace, and the fiber preform. A step of pre-coating the outer peripheral surface of the optical fiber, a step of applying a light-shielding coating agent to the outer peripheral surface of the fiber preform, and a step of curing the light-shielding coating agent in a curing furnace, and curing the light-shielding coating agent The step of curing in the furnace includes a light energy curing step for performing primary curing, and an infrared curing step for performing secondary curing subsequent to the light energy curing step .

For this reason, the adhesive force between the fiber preform and the light-shielding coating agent layer can be improved by thermal curing with infrared rays while achieving rapid curing of the light-shielding coating agent with ultraviolet rays or visible light .

Preferably, the light-shielding coating agent is provided with light energy curability by at least one of ultraviolet light and visible light, and infrared curability that is cured when irradiated with infrared light .

In order to prevent a decrease in fiber transmittance due to ultraviolet rays, the light-shielding coating agent is provided with light energy curability and heat curability. By lowering the illuminance of the primary curing process with light energy, the glass material can be prevented from lowering the transmittance (coloring) due to ultraviolet rays, and the cured material properties of the coating agent are exhibited by thermal curing in the secondary curing process .

  According to the present invention, a fiber manufacturing method and a fiber capable of preventing the decrease in the transmittance of the fiber and the decrease in the flexibility and toughness of the coated fiber while improving the physical properties of the coating agent and the adhesion to the outer peripheral surface of the glass fiber. Can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  First, a first embodiment will be described with reference to FIG. 1 and FIG.

  As shown in FIG. 1, a glass fiber 10 according to this embodiment includes a fiber preform (a multi-core type conduit or a monofiber composed of a core / cladding) 12 and an outer periphery of the fiber preform 12. And a light-shielding coating agent layer 14 to be coated.

  In this embodiment, the fiber 10 is, for example, a plastic hardness shore A95. That is, the plastic hardness shore A95 of the light-shielding coating agent layer 14. The plastic hardness shore is preferably A75 or more and A100 or less, and particularly preferably A80 or more and A95 or less. This is because if the hardness is too lower than the above-mentioned hardness shore, the light-shielding coating agent layer 14 cannot withstand external force or impact, that is, the glass fiber 10 cannot withstand external force or impact. . On the other hand, if the hardness is too high, the flexibility and toughness of the glass fiber 10 may be impaired.

  Moreover, the light-shielding coating agent layer 14 has an adhesion force between the fiber preform 12 of 14 MPa. In particular, the pressure is preferably 14 MPa or more. The main component of the light-shielding coating agent layer 14 is, for example, acrylic deformed silicone or urethane deformed acrylate.

  As shown in FIG. 2, a fiber manufacturing system 20 for manufacturing the glass fiber 10 described above includes a heating furnace (not shown) for melting a base material 12a, a fiber outer diameter measuring device 22, and an atmospheric pressure plasma apparatus. 24, a pressure die 26, a photocuring device 28, and an infrared heating furnace (not shown).

  The fiber outer diameter measuring device 22 measures the outer diameter of the fiber preform 12 formed by being elongated from the preform 12a.

  The atmospheric pressure plasma device 24 is disposed on the downstream side of the fiber outer diameter measuring device 22. This atmospheric pressure plasma device 24 is arranged to perform a pre-coating process performed before coating the outer peripheral surface of the fiber preform 12. The atmospheric pressure plasma device 24 blows plasma gas generated in a mixed atmosphere of argon gas and oxygen gas from the output port of the atmospheric pressure plasma device 24 to the outer peripheral surface (outer surface) of the fiber preform 12. In this case, it is preferable that the distance from the output port to the fiber preform 12 is within 5 mm.

  The pressurizing die 26 is disposed on the downstream side of the atmospheric pressure plasma device 24. In order to form the light-shielding coating agent layer 14, the pressurizing die 26 has a uniform thickness with a silicone-based light-shielding coating agent imparted with photocurability and thermosetting property applied to the outer peripheral surface of the fiber preform 12 in a pressurized state. Apply as follows.

The photocuring device 28 is an ultraviolet curing device, and temporarily cures (semi-cures) the light shielding coating agent. Here, to suppress the maximum irradiation intensity of ultraviolet light (wavelength 365 nm) to 1000 mW / cm ² or less, the integrated light quantity from 1500 mJ / cm ² and 3000 mJ / cm ^2. The photocuring device 28 is preferably not a device using ultraviolet rays but a photocuring device using visible light.

  Downstream of the light curing device 28, an infrared heating furnace (not shown) that heats the light-shielding coating agent with infrared rays out of the fiber preform 12 coated with the light-shielding coating agent that is cut to an arbitrary length is arranged. It is installed. In this infrared heating furnace, the light-shielding coating agent of the fiber preform 12 coated with the light-shielding coating agent is completely cured by infrared rays at 150 ° C. for 1 hour, slowly cooled, and taken out.

  Therefore, such a glass fiber 10 is manufactured by the following processes.

  As a first step, as shown in FIG. 2, the fiber preform 12 is formed by heating and melting the preform 12a in a heating furnace and drawing.

  As a second step, the outer diameter of the fiber preform 12 is measured by the outer diameter measuring device 22. When it is determined that the fiber preform 12 is formed to have a desired outer diameter, the fiber preform 12 is sent toward the atmospheric pressure plasma device 24.

  When it is determined that the fiber preform 12 is not formed to have a desired outer diameter, the fiber preform 12 is cut out and extracted.

  As a third step, the outer peripheral surface of the fiber preform 12 that has been determined to have a desired outer diameter by the outer diameter measuring device 22 is pre-coated on the outer peripheral surface by the atmospheric pressure plasma apparatus 24. At this time, the atmospheric pressure plasma device 24 blows plasma gas generated in a mixed atmosphere of argon gas and oxygen gas from the output port of the atmospheric pressure plasma device 24 to the outer peripheral surface (outer surface) of the fiber preform 12. The fiber preform 12 thus sprayed with the plasma gas by the atmospheric pressure plasma device 24 is sent toward the pressurizing die 26.

  As a fourth step, in order to form the light shielding coating agent layer 14 on the outer peripheral surface of the fiber preform 12 on which the plasma gas is sprayed, the light shielding coating agent pressurized by the pressure die 26 is made to have a uniform thickness. Apply. The fiber preform 12 thus coated with the light-shielding coating agent by the pressure die 26 is sent toward the photocuring device 28.

As a fifth step, the fiber preform 12 coated with the light-shielding coating agent is irradiated with ultraviolet rays by the photocuring device 28. Here, the maximum irradiation intensity of ultraviolet light (wavelength 365 nm) is at 1000 mW / cm ² or less, the integrated light quantity is 3000 mJ / cm ² from 1500 mJ / cm ^2. The light-shielding coating agent is temporarily cured by such ultraviolet irradiation. As described above, the fiber preform 12 on which the light-shielding coating agent is temporarily cured is sent toward the infrared heating furnace.

  As a sixth step, the fiber preform 12 coated with the light-shielding coating agent preliminarily cured is cut to an arbitrary length. Then, the fiber preform 12 coated with such a light shielding coating agent is placed in an infrared heating furnace to completely cure the light shielding coating agent. At this time, the fiber preform 12 coated with the light shielding coating agent is placed in a heating furnace at 150 ° C. for 1 hour to completely cure the light shielding coating agent. That is, the light shielding coating agent layer 14 is formed on the outer peripheral surface of the fiber preform 12. Thereafter, the inside of the infrared heating furnace is gradually cooled, and the fiber preform 12 having the light-shielding coating agent layer 14 formed on the outer peripheral surface is taken out.

  In this way, the fiber preform 12, that is, the glass fiber 10, in which the light shielding coating agent layer 14 is formed on the outer peripheral surface is produced. The glass fiber 10 thus manufactured is, for example, a plastic hardness Shore A95, and the adhesion between the light shielding coating agent layer 14 and the fiber preform 12 is, for example, 14 MPa.

  The operation of the glass fiber 10 manufactured using the fiber manufacturing system 20 according to this embodiment will be described.

  The pretreatment for coating the fiber preform 12 by the plasma gas emission of the atmospheric pressure plasma device 24 improves the wettability of the light shielding coating agent applied to the outer peripheral surface of the fiber preform 12. For this reason, when the light shielding coating agent is cured on the outer peripheral surface of the fiber preform 12, the adhesion between the fiber preform 12 and the light shielding coating agent layer 14 is improved.

  Further, by reducing the ultraviolet irradiation intensity and irradiation amount of the photocuring device (light energy curing device) 28 and only temporarily curing the light-shielding coating agent, discoloration due to oxidation of other component materials is suppressed. .

  As the main curing of the light-shielding coating agent, the light-shielding coating agent is thermally cured in an infrared heating furnace, thereby completing the curing reaction of the light-shielding coating agent that has been insufficiently cured by the ultraviolet irradiation by the light energy curing device 28. For this reason, the physical properties of the light-shielding coating agent layer 14 are ensured in a desired state, and the required characteristics of the glass fiber 10 are ensured in a desired state.

  As described above, according to this embodiment, the following effects can be obtained.

  Surface treatment of the fiber preform 12 by coating pretreatment with the atmospheric pressure plasma apparatus 24 becomes possible, and the adhesion of the light-shielding coating agent layer 14 to the fiber preform 12 can be improved.

  Further, by avoiding the influence of light energy (ultraviolet rays) as much as possible when the light-shielding coating agent is cured, it is possible to prevent a decrease in light transmittance due to coloring. Therefore, even if the light shielding coating agent layer 14 is coated on the outside of the fiber preform 12, high transparency can be secured.

  Further, the light-curing coating agent is cured in two stages using ultraviolet rays and visible rays of the photocuring device 28 and infrared rays of an infrared heating furnace, so that the light-curing coating agent is rapidly cured by the ultraviolet rays and visible rays of the photocuring device 28. Thus, the adhesion between the fiber preform 12 and the light-shielding coating agent layer 14 can be improved by thermal curing with infrared rays in an infrared heating furnace.

  Furthermore, since the physical properties of the light-shielding coating agent layer 14 can be ensured in a desired state, generation of scratches on the light-shielding coating agent layer 14 can be prevented. Therefore, the glass fiber 10 produced in the above-described process can prevent the generation of scratches against external force and can obtain flexibility and toughness.

  Next, a second embodiment will be described with reference to FIG. This embodiment is a modification of the fiber manufacturing system 20 according to the first embodiment. The same members as those described in the first embodiment are denoted by the same reference numerals, and detailed description will be given. Omitted.

  Here, as shown in FIG. 3, when the atmospheric pressure plasma apparatus 24 is used, a reflection plate 24a is also used. A substantially U-shaped reflector 24a is installed at a position sandwiching the fiber preform 12 with respect to the output port of the atmospheric pressure plasma device 24 in accordance with the opening width of the output port. The reflecting plate 24a is provided with a U-shaped guide plate, for example, mirror-deposited on quartz glass or a metal material. For this reason, the plasma gas escaped to the periphery of the fiber preform 12 can be collected and reflected by the reflecting plate 24 a and applied to the back surface of the fiber preform 12.

  Instead of using the reflector 24a, the atmospheric pressure plasma devices 24 may be installed to face each other under the same conditions. That is, two atmospheric pressure plasma devices 24 may be used.

  The manufacturing process and operation of the glass fiber 10 are the same as the manufacturing process and operation described in the first embodiment, and a description thereof will be omitted.

  As described above, according to this embodiment, the following effects can be obtained.

  By using the reflector 24a at a position facing the plasma gas outlet of the atmospheric pressure plasma device 24, or using two atmospheric pressure plasma devices 24 so that the plasma gas outlets face each other, the fiber preform 12 The coating pretreatment for can be more reliably performed over the entire circumference of the fiber preform 12.

  Although several embodiments have been specifically described so far with reference to the drawings, the present invention is not limited to the above-described embodiments, and all the embodiments performed without departing from the scope of the invention are described. Including implementation.

  According to the above description, the following matters can be obtained. Combinations of the terms are also possible.

[Appendix]
(Additional Item 1) A step of forming a glass fiber by heating and melting a fiber preform in a heating furnace and drawing it;
A step of pre-coating the outer peripheral surface of the glass fiber;
Applying a light-shielding coating agent to the outer peripheral surface of the glass fiber;
In the method of manufacturing the shading coating agent by a step of curing in a curing furnace,
In the fiber manufacturing method and the fiber, the step of pre-coating the outer peripheral surface of the glass fiber is performed by an atmospheric pressure plasma apparatus.

(Additional Item 2) A step of forming a glass fiber by heating and melting and drawing a fiber preform in a heating furnace;
A step of pre-coating the outer peripheral surface of the glass fiber;
Applying a light-shielding coating agent to the outer peripheral surface of the glass fiber;
In the method for producing the shading coating agent by the step of curing in a curing furnace,
A fiber manufacturing method and a fiber, wherein the light-shielding coating agent is a light-shielding coating agent imparted with light energy curability and thermosetting by ultraviolet light or visible light.

(Additional Item 3) A step of forming a glass fiber by heating and melting a fiber base material in a heating furnace and drawing,
A step of pre-coating the outer peripheral surface of the glass fiber;
Applying a light-shielding coating agent to the outer peripheral surface of the glass fiber;
In the method for producing the shading coating agent by the step of curing in a curing furnace,
The fiber curing method and the fiber are characterized in that the step of curing the light-shielding coating agent in a curing furnace includes primary curing as a light energy curing step and secondary curing as an infrared curing step.

    (Additional Item 4) A fiber characterized in that the physical property after curing of the coating agent according to Additional Item 2 is a coating agent having a plastic hardness Shore A75 or more and an adhesive force after optical energy curing and heat curing of 14 MPa or more. .

1 is a schematic cross-sectional view of a fiber according to a first embodiment. Schematic which shows the fiber manufacturing apparatus which concerns on 1st Embodiment. Schematic which shows the fiber manufacturing apparatus which concerns on 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Glass fiber, 12 ... Fiber base material, 12a ... Base material, 14 ... Light shielding coating agent layer, 20 ... Fiber manufacturing system, 22 ... Fiber outer diameter measuring device, 24 ... Atmospheric pressure plasma apparatus, 26 ... Pressure die | dye, 28 ... Light curing device

Claims (6)

A fiber preform is formed by drawing the preform in a state where the preform is heated and melted in a heating furnace,
Pre-coat the outer peripheral surface of the fiber preform,
Applying a light-shielding coating agent having light energy curability by at least one of ultraviolet rays and visible light and infrared curability by infrared rays to the outer peripheral surface of the fiber preform,
Said light-shielding coating agent is cured in a curing oven, Ri Na to form a light-shielding coating agent layer,
The light-shielding coating agent is precured by irradiating the light energy before the infrared light, and completely cured by irradiating the infrared light after the light energy irradiation, and the infrared light is irradiated first. A fiber characterized in that the light-shielding coating agent is made more transparent than when the light energy is irradiated later . 2. The fiber according to claim 1 , wherein the light-shielding coating agent layer has a plastic hardness Shore A75 or more, and an adhesion force of the light-shielding coating agent to the fiber base material after light energy curing and heat curing is 14 MPa or more. . A fiber preform is formed by drawing the preform in a state where the preform is heated and melted in a heating furnace,
Pre-coat the outer peripheral surface of the fiber preform,
Applying a light-shielding coating agent to the outer peripheral surface of the fiber preform,
The light shielding coating agent is irradiated with light energy to primarily cure the light shielding coating agent,
And irradiating infrared rays to the light-shielding coating agent wherein the light-shielding coating agent is cured secondary and after curing the primary, Ri Na to form a light-shielding coating agent layer,
A fiber characterized in that the light-shielding coating agent is made more transparent than when the infrared ray is irradiated first and the light energy is irradiated later . The fiber according to claim 3 , wherein the light energy is at least one of ultraviolet rays and visible rays. Forming a fiber preform by drawing the preform in a state where the preform is heated and melted in a heating furnace;
Pre-coating the outer peripheral surface of the fiber preform;
Applying a light-shielding coating agent to the outer peripheral surface of the fiber preform;
Curing the light-shielding coating agent in a curing furnace,
The step of curing the light-shielding coating agent in a curing furnace includes a light energy curing step in which primary curing is performed, and an infrared curing step in which secondary curing is performed following the light energy curing step. Method.   6. The fiber production according to claim 5, wherein the light-shielding coating agent has optical energy curability by at least one of ultraviolet rays and visible rays, and infrared curability that is cured when irradiated with infrared rays. Method.

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